I. Energy

A. Conventional1. Fossil Fuels

b. Coal• Electricity generation (60% of global coal use, 2008)• Main fuel source in China for industry• Use expected to grow, mostly fueled by Asia,

especially China (78% of global growth) and India• Benefits

• Inexpensive• Abundant, easy to recover• Requires minimal processing• Existing technology & infrastructure

• Concerns• Environmental degradation from mining• Requires extensive transportation system (rail)• Combustion pollutants (CO2, PM, Hg, NOx, SOx)• Counter: “Clean coal” (requires more processing)

US EIA

I. Energy

A. Conventional1. Fossil Fuels

c. Natural gas (methane)• Use predicted to grow almost as fast as coal• Equaled coal (BTU basis) in 1999• Increase fueled by price, environmental concerns,

energy security issues, market deregulation• Benefits

• Inexpensive• Abundant, easy to recover• Existing technology & infrastructure• Burns relatively cleanly (little PM, etc.), almost no

solid waste• High efficiency (90% vs. 27% for electricity)• Energy security – US produces 85% of demand vs.

40% for oil• Concerns

• Greenhouse gas• Adequate long-term supply

I. Energy

A. Conventional1. Fossil Fuels

d. Gas (methane) hydrates• Worldwide reserves estimated at up to 100,000

trillion cubic feet of gas (10,000 Gt carbon), twice the carbon in all other fossil fuel reserves on earth

• Located beneath marine sediments at 300-500 m depth

• Common off SE US, Siberia, Alaska• Benefits

• Extremely abundant• Existing infrastructure for distribution• Burns relatively cleanly (little PM, etc.), almost no

solid waste• High efficiency (90% vs. 27% for electricity)• Energy security – US has extensive reserves

• Concerns• Greenhouse gas• Damage to sea floor• Catastrophic effects of massive release

I. Energy

A. Conventional2. Nuclear

• Derived from splitting ("fissioning“) of uranium atoms• Uranium mined, processed to increase fissionable material,

made into fuel rods• Uranium atoms split inside reactor, generate heat steam

electricity• World capacity projected to rise from 379 GW in 2007 to 592 GW

in 2035• Highest growth projected for developing world, especially Asia

• Benefits• Clean (few pollutants or GHGs)• Relatively inexpensive• Existing technology & infrastructure• Compact fuel & waste (high energy density – 1 lb of U =

3.5 million lbs of coal)• Energy security – US has extensive reserves

• Concerns• Safety – Possibility of accidents• Strategic risks – Material stolen and used to create weapon• Waste disposal – Contamination of ground water, soil,

animals, plants, people• GHG production from mining & transportation of uranium

US EIA

US EIA

I. Energy

B. Renewable• Sources either can’t be used up or are replenished

quickly through natural processes• In CA, eligible renewable energy sources include

1) Biomass and waste2) Geothermal3) Solar4) Small hydroelectric5) Wind energy

• Use for electricity generation expected to increase by 128.5% (3%/year) worldwide between 2007 and 2035

• 18% of total electricity generation in 2007 23% in 2035• Growth in renewable energy resources expected to be

constrained by moderate fossil fuel prices• Renewable energy development expected to be

increases in hydroelectric (54%), esp. in non-OECD Asia & Brazil, and wind (26%), esp. in China

I. Energy

B. Renewable1. Hydroelectric

• Currently supplies ~20% of electricity production worldwidea. Small (<30 MW)

• Less impact but less power than large facilitiesb. Large (>30 MW)

• Includes immense dams with potentially large impacts• Ex – Itaipu Dam (Brazil, Paraguay, Argentina) = 12,600 MW• Ex – Three Gorges Dam (China) = 18,200 MW

• Benefits• Inexpensive, once facility exists• Minimal environmental impact – Little pollution, no GHGs• Many facilities already in place• May permit flood control• Relatively efficient and nondestructive

• Concerns• Limited use geographically• Environmental degradation in flooded areas• Environmental degradation downstream• Detrimental to some aquatic animals (Ex – salmon)• Tropical dams trap organic material methane• Rainfall variation can reduce reliability

http://www.nwd-wc.usace.army.mil/report/colmap.htm

I. Energy

B. Renewable2. Wind

• Power captured with wind turbines• The Dakotas and Texas have sufficient wind capacity to

supply energy needs of entire United States• Benefits

• “Free”• Minimal environmental impact – Little pollution, no

GHGs• Can produce electricity without being connected to

power grid• Multiple uses of land

• Concerns• Limited use geographically• Inconsistent energy source• Expensive to maintain• May be dangerous to birds/bats• Low power density• Eyesores (offshore?)• Weather effects?

Skegness

I. Energy

B. Renewable3. Solar

• Can be generated bya. Focusing heat of sun on central point that heats up; heat used to

produce steam, which turns turbineb. Photovoltaic (PV) cells – Convert energy from sun directly to

electricity; each PV panel typically produces small amount of electricity, but panels can be grouped

• Benefits• Abundant – “The amount of solar radiation striking the

earth over a three-day period is equivalent to the energy stored in all fossil energy sources.”

• “Free”• Minimal environmental impact – Little pollution, no GHGs• PV systems have no moving parts, need little maintenance• Can produce electricity without being connected to power

grid• Concerns

• Limited use geographically• Inconsistent energy source• Expensive: $0. 17-0.32/kWh vs. $0.04-0.06/kWh on latest bill• Requires special materials to harvest energy• Low power density; long-term storage of energy